CURRENCY
You are not allowed to bring Indian currency into the country, or take it with you when you leave. The Rupee is fully convertible so there's not much of a black market, even though you'll constantly be haunted by offers to 'change money'. In cities you can change most major foreign currencies and brands of travellers' cheques - but you'll widen your options and save yourself hassles if you stick to US dollars or pounds Sterling or Euros and either Thomas Cook or American Express travellers cheques. In fact, it's wise to bring a couple of different brands of cheques in different currencies since some branches of some banks have particular idiosyncrasies, such as refusing to handle X-brand of travellers' cheques in pounds Sterling denomination or Y-brand in US dollars.
When changing money at a bank you'll need the patience of a saint and the paperwork skills of a ledger clerk, especially in smaller towns. The secret is to change money in large amounts as infrequently as possible and preferably in big banks in big cities. You are supposed to be given an encashment certificate when you change money at a bank or an official moneychanger. Some hotels insist you show an encashment certificate before accepting payment in Indian rupees. If you stay in India more than four months, you'll need to keep a handful of these certificates to get income tax clearance. Most of the reputed hotels in big cities have good exchange rate unlike many other countries where you don’t get good exchange rate at the hotels.
Credit cards are widely accepted in Indian cities and larger towns, particularly American Express, Diners Club, MasterCard and Visa. Credit cards can also be used to get cash advances in rupees. The Bank of Baroda seems to be the most efficient bank at handling such transactions. A growing number of large cities and towns have ATMs that accept Cirrus, Maestro, Mastercard and Visa.
Indian currency notes circulate far longer than in the West and the small notes in particular become very tatty - some should carry a government health warning. You may occasionally find that when you try to pay for something with a ripped or grubby note that your money is refused. You can change old notes for new ones at most banks or save them and use them creatively as tips. Don't let shopowners palm grubby notes off on you as change - simply hand them back and you'll usually be given a note slightly higher up the acceptability scale. Keep a supply of smaller denomination notes - there is a perpetual shortage of small change.